Xylomollin derivatives for use as insect feeding deterrents

ABSTRACT

Synthetic derivatives or intermediates of xylomollin are identified which can be used as insect feeding deterrents. The identified derivatives or intermediates exhibiting antifeeding activity include glutaraldehyde and carbocyclic or heterocyclic dialdehydes wherein the aldehyde groups are positioned on adjacent carbons of the carbocyclic or heterocyclic rings. The active compounds also include the hemiacetal hemiacetal equivalents, the acetal hemiacetal equivalents and the vinyl ether equivalents of the dialdehydes.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 08/820,840,entitled XYLOMILLON DERIVATIVE INSECT FEEDING DETERRENTS, filed Mar. 20,1997, now U.S. Pat. No. 5,804,598 and application Ser. No. 60/013,817filed Mar. 21, 1996, entitled INSECT FEEDING DETERRENTS AND THEIRSYNTHESIS.

BACKGROUND OF THE INVENTION

The present invention relates to the identification of compounds whichdeter feeding by insects and in particular such compounds which arestructurally related to xylomollin, a naturally occurring feedingdeterrent.

Heavy use of insecticides presents environmental dangers and promotesthe development of resistant insect populations. One alternative topresent practices relating to insecticide use involves the applicationon crops of chemicals which inhibit or deter feeding thereon by insects.Use of naturally occuring feeding deterrants and their derivatives forcrop protection is appealing because such compounds do not need to betoxic to work and therefore the additional concerns of toxicity to otheranimals, and in particular to mammals, are avoided. Folklore and storiesof traditional farming practices are replete with references to feedingdeterrent or repellent properties of plants. A well known practiceinvolves the placement of hedge apples in the corners of basements orroot cellars to repel crickets and other insects, spiders and even somerodents.

Extracts from plants known to exhibit antifeeding activity have beenused in compositions developed for commercial utilization. For example,U.S. Pat. No. 5,290,557 to Mason et al. discloses the use of saponincontaining extracts of Yucca schidigera as an antifeedant to controlterrestrial molluscs. Similarly, U.S. Pat. No. 4,676,985 to Gould et al.discloses a process of protecting crops from damage by coating seeds orseedlings with an extract from plants having feeding deterrent activitysuch as extracts from butterfly milkweed, English ivy, santolina,bergamot, clary and swamp milkweed.

Others have focused on identifying derivatives of naturally occuringinsect feeding deterrants which also exhibit feeding deterrant activityand which can be synthesized commercially. U.S. Pat. No. 5,047,242 toKlocke et al. identifies derivatives of azadirachtin which exhibitantifeedant activity. Azadirachtin is a naturally occuring feedingdeterrant which can be isolated from the seeds of the neem tree and fromthe fruits of the chinaberry tree. U.S. Pat. No. 4,960,791 to Klocke etal. identifies antifeedant derivatives of salannin which is a naturallyoccuring insect antifeedant related to azadirachtin. U.S. Pat. No.4,855,319 to Mikolajczak et al. discloses use of asimicin as a feedingdeterrent. Asimicin is a derivative of tetrahydrofuranoid acetogenins,which are characteristic of the Annonaceae plant family and knownfeeding deterrants.

As of yet, it does not appear that any of these compositions haveachieved wide-spread commercial use or success. The lack of commercialsuccess of such compositions may be due to the relative high cost inobtaining large quantities of the specified plant extracts or insynthesizing the relatively complex chemical derivatives of naturallyoccuring antifeedants identified to date. Derivatives of naturallyoccurring feeding deterrents still provide a promising avenue foralternatives to currently available insecticides for use in integratedpest management programs. The compounds should be ecologically sound andnon-toxic to mammals. The synthesis of these compounds should berelatively inexpensive and result in the production of relatively stablecompounds with the minimal structural components necessary forrelatively high activity.

Xylomollin, which has the following chemical formula: ##STR1## is foundin the unripened fruit of the East African tree Xyloccarpus molluscensis(Meliaceae) and has been previously identified as a potent feedingdeterrent. However, due to the complexity of xylomollin's chemicalstructure, currently known methods of synthesizing xylomollin areprohibitively expensive for commercial purposes.

SUMMARY OF THE INVENTION

The present invention includes the identification of syntheticderivatives or intermediates of xylomollin which can be used as feedingdeterrents.

The identified derivatives or intermediates exhibiting antifeedingactivity include glutaraldehyde and carbocyclic or heterocyclicdialdehydes wherein the aldehyde groups are positioned on adjacentcarbons of five or six member ring compounds as represented by thefollowing formulas: ##STR2## where ring B is a five or six carbon ringor a lactone that may include an alkene function and/or alkyl orhydroxyl groups as substituents. The active compounds also include theacetal hemiacetal equivqalents thereof, the hemiacetal hemiacetalequivalents thereof and vinyl ether equivalents thereof.

The acetal hemiacetal and hemiacetal hemiacetal equivalents of thecarbocyclic and heterocyclic compounds include: ##STR3## where ring B isa five or six carbon ring or a lactone that may include an alkenefunction, R₁ and R₂ comprise H, OH or an alkyl group and R₃ and R₄comprise H or an alkyl group. The alkyl groups are preferrably C₁ -C₅alkyl groups, and at least one of R₃ and R₄ must comprise H.

The vinyl ether equivalents of the carbocylic and heterocyclic include:##STR4## where ring B is a five or six carbon ring or a lactone that mayinclude an alkene function, R₁ and R₂ comprise H, OH or an alkyl groupand R₃ comprises H or an alkyl group. The alkyl groups are preferrablyC₁ -C₅ alkyl groups.

OBJECTS AND ADVANTAGES OF THE INVENTION

The objects of the present invention include: providing feedingdeterrent compositions which are relatively non-toxic and relativelyinexpensive to manufacture and to apply at concentrations which areeffective at deterring feeding on plants and crop material; providingsuch compositions which are relatively easy to manufacture; providingsuch compositions which are effective at deterring feeding even atrelatively low concentrations with respect to plant or crop material towhich the compositions are applied; and providing such compositionswhich are relatively biodegradable.

It is a further object of this invention to identify the functionalgroups of naturally occuring xylomollin which account for the feedingdeterrent effect of xylomollin and to identify synthetic derivativeswhich incorporate these functional groups and function as feedingdeterrents but are relatively non-toxic and relatively inexpensive tomanufacture and to apply at concentrations which are effective atdeterring feeding on plants and crop material.

Other objects and advantages of this invention will become apparent fromthe following description wherein are set forth, by way of illustrationand example, certain embodiments of this invention.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific composition and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

The present invention comprises the use of glutaraldehyde and variouscarbocyclic and heterocyclic dialdehydes and derivatives thereof asfeeding deterrents. The carbocyclic and heterocyclic dialdehydesidentified for use as feeding deterrents generally include thefollowing: ##STR5## where ring B is a five or six carbon ring or alactone that may include an alkene function and/or alkyl or hydroxylgroups as substituents. The active compounds also include the acetalhemiacetal equivalents thereof, the hemiacetal hemiacetal equivalentsthereof and vinyl ether equivalents thereof.

The active compounds also include the acetal hemiacetal, hemiacetalhemiacetal and vinyl ether derivatives of the above noted dialdehydes.The acetal hemiacetal and hemiacetal hemiacetal equivalents of thecarbocyclic and heterocyclic compounds include: ##STR6## where ring B isa five or six carbon ring or a lactone that may include an alkenefunction, R₁ and R₂ comprise H, OH or an alkyl group and R₃ and R₄comprise H or an alkyl group. The alkyl groups are preferrably C₁ -C₅alkyl groups, and at least one of R₃ and R₄ must comprise H. The vinylether equivalents of the carbocylic and heterocyclic include: ##STR7##where ring B is a five or six carbon ring or a lactone that may includean alkene function, R₁ and R₂ comprise H, OH or an alkyl group and R₃comprises H or an alkyl group. The alkyl groups are preferrably C₁ -C₅alkyl groups.

In the presence of water, the acetal vinyl ether derivative will breakdown to the acetal hemiacetal derivative, a portion of which then breaksdown to the dialdehyde. A portion of the hemiacetal hemiacetalderivative interconverts to and exists in equilibrium with thedialdehyde. Similarly a portion of the acetal hemiacetal derivative willconvert to the dialdehyde in an aqueous solution. The vinyl etherderivatives are generally more stable than the acetal hemiacetalderivatives and the hemiacetal hemiacetal deriviatives which tend to bemore stable than the dialdehyde equivalents. Therefore the preferredcompounds for use would generally comprise the vinyl ether derivatives,the acetal hemiacetal derivatives and the hemiacetal hemiacetalderivatives which are then converted to the dialdehyde in theapplication environment through the reaction with water present therein.

It has been postulated that an insect food sensory protein has amino andthiol groups with rigid steric requirements for binding via conjugateaddition/redox reaction or imine/heterocycle formation with activecompounds. It has been further postulated that the aldehyde functionalgroups on the xylomollin dialdehyde derivative bind with the insect foodsensory protein to deter feeding generally as follows: ##STR8##

It is not exactly known how this reaction deters feeding. The reactionis believed to effect the insect nervous system and interfere with theinsects ability to process information concerning food possiblysuppressing hunger or decreasing the palatability of the treated food.The active compounds may also arrest insect development beyond thelarval stage.

The following compounds have been tested and have shown feedingdeterrent effect: ##STR9## The results of the testing are reported belowwith reference to the corresponding reference numerals noted above.

In addition to the above noted compounds, preferred active compounds forfeeding deterrent effect generally include the following along withisomers thereof: ##STR10## compounds and their corresponding dialdehydesand vinyl ethers.

Glutaraldehyde (compound 1 above) free of polymerization products wasprepared by saturating 25 ml of a 25% aqueous solution of glutaraldehydewith sodium chloride and extracting the mixture with three 50 mlportions of dichloromehtane. The combined extracts were dried withsodium sulfate and the solvent was removed on a rotary evaporator underwater aspirator vacuum using a water bath at 30 degrees Centigrade. Thepure sample of glutaraldehyde thus obtained was used within 3 days forbioassays.

To produce compound 2, a solution of 1.14 g or 10 mmol 2-methoxy-3,4dihydropyran (compound 3 which is commercially available) and 0.18 g or10 mmol of water in 20 ml of acetonitrile was stirred with 2.0 g ofAmberlyst-15 (H⁺) resin for 4 hours. The resin was removed by filtrationand the solvent was removed by rotary evaporation to give a colorlessliquid that was 90-92% compound 2 and 4-6% glutaraldehyde (compound 1)according to NMR spectroscopy.

To produce compound 4, a mixture of 2,3-dimethyl-1,3-butadiene (0.328 g,4 mmol), 2,5-demethoxy-2,5-dihydrofuran (0.520 g, 4 mmol), 0.25 ml ofwater and 50 mg of hydroquinone in a sealed vial was heated in an oilbath at 70 degreees Fahrenheit for 12 hours. The resulting mixtureconsisted of two liquid phases, the lower of which contained 90% ofcompound 4.

To produce compound 5, the procedure describe above for compound 4 wasused except that the volume of water was 0.070 ml. A homogeneous mixturewas formed consisting of 90% of compound 5 plus 3-4% of compound 4, 3-4%of the corresponding cyclic dimethy acetal and 2-4% of startingmaterial.

Compounds 6 and 7 can be produced using the same procedure as describedabove for compounds 4 and 5 but using 1,3 butadiene instead of2,3-dimethyl-1,3-butadiene as the starting material.

Although the carrier utilized in the tests discussed below comprises anorganic solvent, ethyl acetate, it is not intended that the presentapplication be limited to any particular carrier and it is foreseen thatthe active compounds of the present invention could be applied utilizinga wide range of carriers or formulations now known or subsequentlydeveloped. It is foreseen that the active compounds could be applied tocrop or plant material in liquid or solid compositions or in solidsuspensions or without a carrier. Possible carriers include water orvegetable oil It is also foreseen that a wide range of additives couldalso be utilized in the feeding deterrent compositions to facilitateapplication, to stabilize the composition and for other reasons wellknown in the art.

The feeding deterrent effect of the active compounds was evaluatedthrough choice tests and weight gain tests on third to fifth instarlarvae of Tenebrio molitor (mealworm, flour beetle larvae), third-instarlarvae of Manduca sexta (tomato hornworm) and with juvenile Achetadomestica (common cricket). Screening for toxicity was done with larvaeof Artemia salina (brine shrimp). Insect cultures and food were obtainedfrom Carolina Biological Supply Co., Burlington, N.C.

Test compounds in an ethyl acetate solution were applied by pipet to aweighed food sample and the mixture was stirred thoroughly in glass orstainless steel trays. References to concentrations of test compoundsare reported as parts per million (ppm) by weight of pure test compoundrelative to the weight of the food sample. Treated food was left in opentrays for twenty-four hours before insects were introduced. Controls offood treated with ethyl acetate were prepared according to the sameprocedure. Insect trials with food treated by solvent only (control)versus food with no treatment showed no evidence of solvent residueeffects.

For the choice tests, forty T. molitor larvae were placed on a trayhaving a first and a second supply of bran meal (60 grams each) onopposite ends thereof. The larvae were placed in groups on each foodsupply. The first supply of bran meal was treated with a solution of thetest compound and the carrier, ethyl acetate as noted above. The testcompound was applied to the food at a selected concentration (generally400, 800 or 1000 parts per million, i.e. weight of test compound toweight of bran meal). The second supply of bran meal was treated with anequivalent amount of ethyl acetate as noted above. The second supply offood may be referred to as untreated food. The first and second suppliesof bran meal were maintained in separate areas in the containerseparated by a screen across which the larvae could traverse. The trayswere covered with lids that allowed air flow.

The number of larvae at each end were counted at 7-day intervals. Thepercentage of larvae on the control or untreated food is indicative ofthe feeding deterrent effect of the test compound.

Growth tests of T molitor were done by putting 40 larvae on 120 grams oftreated and untreated food and periodically weighing the insects. Weightgain for insects on treated food is reported as a percentage of theweight gain for insects on the control or untreated food (i.e. weightgain on treated/weight gain on control). The percentage of dead insectswas also recorded. Typical mortality for the controls were 0% at 7 days,3% at 14 days and 5% at 21 days.

Feeding tests with M. sexta were made by putting one insect in a covereddish containing two 3.5 cm culture dishes. The food was preparedaccording to the formula of Yamamoto reported in Yamamoto, R. T., J.Econ. Entom. 1969, 62, 1427. One dish contained 5.0 grams of foodtreated with the test compound and solvent and the other contained 5.0grams of food treated with solvent only. Each dish was weighed at 1-dayintervals for one week.

Feeding tests were also conducted with azadirachtin, the principleactive component of neem oil, a natural product with well-documentedinsect feeding deterrence. Azadirachtin was obtained from Sigma ChemicalCo., St. Louis, Mo.

Results of feeding tests are shown in Table 2.

Table 1 provides results from the choice tests with T molitor. The tableincludes an indication of the percentage of insect larvae in the area ofthe untreated food (i.e. the percentage which preferred the untreatedfood). The reference to days with each percentage indicates the numberof days from the beginning of the test on which the observation wasmade.

                  TABLE 1                                                         ______________________________________                                        Choice Tests for Glutaraldehyde and its Derivatives                                           Conc.    % Insects on untreated food                          Test Compound                                                                           Insect    (ppm)    (7 days)                                                                              (14 days)                                ______________________________________                                        (1) glutaraldehyde                                                                      T. molitor                                                                              1000     55      48                                         (2) T. molitor 1000 72 56                                                     (3) T. moiltor 1000 52 54                                                   ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        Weight Change Relative to Control                                                             Conc.    % Wt change v. control                               Test Compound                                                                           Insect    (ppm)    (7 days)                                                                              (14 days)                                ______________________________________                                        (1) glutaraldehyde                                                                      T. molitor                                                                              1000     11      45                                         (2) T. molitor 1000 16 32                                                     (3) T. molitor 1000 13 30                                                   ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Feeding Rate Relative to Control                                                                     Conc. % Wt change of treated control                     Test Compound Insect (ppm) (7 days)                                         ______________________________________                                        (5)       M. sexta 400     5                                                    azadirachtin M. sexta 50 100                                                ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Mortality Relative to Control                                                                 Conc.    % Mortality v. control                               Test Compound                                                                           Insect    (ppm)    (7 days)                                                                              (14 days)                                ______________________________________                                        (1) glutaraldehyde                                                                      T. molitor                                                                              1000     0        3                                         (2) T. molitor 1000 3 10                                                      (3) T. molitor 1000 3  5                                                      (4) T. molitor 800 93  20*                                                    (5) T. molitor 400 40 92                                                      azadirachtin T. molitor 2 NA 50                                             ______________________________________                                         *The 20% mortality rate represents the mortality rate on the 14th day         after treatment of the food and in which the insects were introduced to       the food seven days after treatment of the food as opposed to 24 hours fo     the other assays and for a new group of insects.                         

Although test compounds 1-3 only appears to show a slight feedingdeterrent effect with respect to the choice test, the feeding deterrenteffect of these compounds with respect to the weight change tests issignificant. Similarly results of the test comparing the weight changeof the food treated with test compound 5 versus food treated with acontrol and fed upon by M. sexta showed significant feeding deterrenteffect particularly when compared to the results of a similar test withAzadirachtin. Although the mortality rate of insects which fed upon foodtreated with test compounds 4 and 5 appeared relatively high, it isunclear as to whether the test compounds 4 and 5 are toxic at thedosages utilized or whether the feeding deterrent effect resulted in thehigh mortality rate. For example, the compounds may prevent the insectfrom feeding or prevent the insect from developing properly which mayresult in death.

Tests done on an acetal acetal equivalent of test compounds 4 and 5indicated no feeding deterrent effect. Additional research is necessaryto reach any conclusions as to whether the acetal acetal equivalents ofany of the above described compounds will exhibit feeding deterrent orantifeedant activity effect. In addition, it is foreseeable that theacetal acetal equivalents might be applicable for feeding deterrenteffect in that they may gradually break down to the active equivalentsso as to be usable in a time released type application.

Although the active compounds disclosed herein are discussed for use indeterring insects from feeding of plant and crop material and the likeit is foreseen that the active compounds may also exhibit a feedingdeterrent effect on terrestrial mollusks, nematodes or other relatedcreatures which feed on plant and crop material.

Further it is foreseen that various chemical equivalents or isomers ofthe specified active compounds may also provide a feeding deterrenteffect.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or compositions, equivalents or isomers described andshown.

What is claimed and desired to be secured by Letters Patent is asfollows:
 1. A method of deterring the feeding activity of insects onplant and crop material comprising the step of applying an insectantifeedant effective amount of an active compound of the formula:##STR11## wherein ring B is a 5 or 6 carbon ring, or a lactone, that mayinclude an alkene function and R₁ is H, OH or an alkyl, R₂ is H, OH oran alkyl and R₃ is H or an alkyl.
 2. The method as in claim 1 whereinsaid step of applying comprises applying an insect antifeedant effectiveamount of a dialdehyde equivalent of said active compound.
 3. The methodas in claim 1 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 4. The method as in claim 1 wherein said active compoundcomprises: ##STR12## wherein ring B may include an alkene function andR₁ is H, OH or C₁ -C₅ alkyl, R₂ is H, OH or C₁ -C₅ alkyl and R₃ is H ora C₁ -C₅ alkyl.
 5. The method as in claim 4 wherein said step ofapplying comprises applying an insect antifeedant effective amount of adialdehyde equivalent of said active compound.
 6. The method as in claim4 wherein said step of applying comprises applying an insect antifeedanteffective amount of a vinyl ether equivalent of said active compound. 7.The method as in claim 1 wherein said active compound comprises:##STR13## wherein R₃ is H or a C₁ -C₅ alkyl.
 8. The method as in claim 7wherein said step of applying comprises applying an insect antifeedanteffective amount of a dialdehyde equivalent of said active compound. 9.The method as in claim 7 wherein said step of applying comprisesapplying an insect antifeedant effective amount of a vinyl etherequivalent of said active compound.
 10. The method as in claim 1 whereinsaid active compound comprises: ##STR14##
 11. The method as in claim 10wherein said step of applying comprises applying an insect antifeedanteffective amount of a dialdehyde equivalent of said active compound. 12.The method as in claim 10 wherein said step of applying comprisesapplying an insect antifeedant effective amount of a vinyl etherequivalent of said active compound.
 13. The method as in claim 1 whereinsaid active compound comprises:
 14. The method as in claim 13 whereinsaid step of applying comprises applying an insect antifeedant effectiveamount of a dialdehyde equivalent of said active compound.
 15. Themethod as in claim 13 wherein said step of applying comprises applyingan insect antifeedant effective amount of a vinyl ether equivalent ofsaid active compound.
 16. The method as in claim 1 wherein said activecompound comprises:
 17. The method as in claim 16 wherein said step ofapplying comprises applying an insect antifeedant effective amount of adialdehyde equivalent of said active compound.
 18. The method as inclaim 16 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 19. The insect antifeedant composition as in claim 1 whereinsaid active compound comprises:
 20. The method as in claim 19 whereinsaid step of applying comprises applying an insect antifeedant effectiveamount of a dialdehyde equivalent of said active compound.
 21. Themethod as in claim 19 wherein said step of applying comprises applyingan insect antifeedant effective amount of a vinyl ether equivalent ofsaid active compound.
 22. A method of deterring the feeding activity ofinsects on plant and crop material comprising the step of applying aninsect antifeedant effective amount of an active compound of theformula: wherein ring B is a 5 or 6 carbon ring, or a lactone, that mayinclude an alkene function and R₁ is H, OH or an alkyl, R₂ is H, OH oran alkyl, R₃ is H or an alkyl and R₄ is H or an alkyl, and at least oneof R₃ and R₄ must be H.
 23. The method as in claim 22 wherein said stepof applying comprises applying an insect antifeedant effective amount ofa dialdehyde equivalent of said active compound.
 24. The method as inclaim 22 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 25. The method as in claim 22 wherein said active compoundcomprises: ##STR15## wherein ring B may include an alkene function andR₁ is H, OH or C₁ -C₅ alkyl, R₂ is H, OH or C₁ -C₅ alkyl, R₃ is H or aC₁ -C₅ alkyl and R₄ is H or a C₁ -C₅ alkyl, and at least one of R₃ andR₄ must be H.
 26. The method as in claim 25 wherein said step ofapplying comprises applying an insect antifeedant effective amount of adialdehyde equivalent of said active compound.
 27. The method as inclaim 25 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 28. The method as in claim 25 wherein: R₁ is H, OH or CH₃ ; R₂is H, OH or CH₃ ; R₃ is H or CH₃ and R₄ is H or CH₃ ; and at least oneof R₃ and R₄ must be H.
 29. The method as in claim 28 wherein said stepof applying comprises applying an insect antifeedant effective amount ofa dialdehyde equivalent of said active compound.
 30. The method as inclaim 28 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 31. The method as in claim 22 wherein said active compoundcomprises: ##STR16## R₃ is H or a C₁ -C₅ alkyl and R₄ is H or a C₁ -C₅alkyl, and at least one of R₃ and R₄ must be H.
 32. The method as inclaim 31 wherein said step of applying comprises applying an insectantifeedant effective amount of a dialdehyde equivalent of said activecompound.
 33. The method as in claim 31 wherein said step of applyingcomprises applying an insect antifeedant effective amount of a vinylether equivalent of said active compound.
 34. The method as in claim 31wherein R₃ is H or CH₃ and R₄ is H or CH₃, and at least one of R₃ and R₄must be H.
 35. The method as in claim 34 wherein said step of applyingcomprises applying an insect antifeedant effective amount of adialdehyde equivalent of said active compound.
 36. The method as inclaim 34 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.
 37. A method of deterring the feeding activity of insects onplant and crop material comprising the step of applying an insectantifeedant effective amount of an active compound of the formula:##STR17## wherein R₁ is H or an alkyl.
 38. The method as in claim 34wherein said step of applying comprises applying an insect antifeedanteffective amount of a dialdehyde equivalent of said active compound. 39.The method as in claim 34 wherein said step of applying comprisesapplying an insect antifeedant effective amount of a vinyl etherequivalent of said active compound.
 40. The method as in claim 37wherein R₁ is H or CH₃.
 41. The method as in claim 40 wherein said stepof applying comprises applying an insect antifeedant effective amount ofa dialdehyde equivalent of said active compound.
 42. The method as inclaim 40 wherein said step of applying comprises applying an insectantifeedant effective amount of a vinyl ether equivalent of said activecompound.